You are correct and not overly suspicious...
the marinated meats at the grocery are the expired meats. The sweet and salty glop they put on them hides the uglieness.
I'm so turned off with commercial meat processing that some friends and I are going in on a local yearling steer for the freezer. Local, pasture grazed, grain finished, no hormones, no antibiotics, and only $2.19/lb!!!! I'm also buying fresh organic field chickens, pork, and lamb from local farmers as well as eggs.